zaifSubscribe.js

const url = "wss://ws.zaif.jp/stream?currency_pair=btc_jpy"
const WebSocket = require('ws')
const wss = new WebSocket(url)
wss.on('open', () => {
    console.log('Connection open')
})
wss.on('close', () => {
    console.log('Connection close')
})
wss.on('message', (dataString) => {
    console.log('New message')
    const json = JSON.parse(dataString)
    console.log(json)
})
setTimeout(() => {
    wss.terminate()
}, 10000)